The main limitation in measuring obscured star formation at the highest redshifts has been the difficulty to detect and measure the dust emission of individual high-redshift galaxies using far-infrared/sub-millimetre facilities such as the Herschel Space Observatory and single-dish sub-mm observatories. Due to their poor resolution and sensitivity (see, e.g., figure 10 of [1]}), observations with these facilities suffer from important confusion noise, which limited the study of high-redshift sources to only the brightest objects, such as quasars (e.g., [2]}) and sub-millimetre galaxies (SMGs; e.g., [3]}, [4]}). Alternatively, several studies attempted to overcome the confusion limits and detect fainter galaxies using stacking (e.g., [5]}) and de-blending techniques (e.g., [6]}, [7]}), but these approaches have limitations. With its unprecedented sensitivity and spatial resolution at (sub-)millimetre wavelengths, the Atacama Large Millimetre/Sub-millimetre Array (ALMA), has revolutionised this field, allowing us to directly detect, for the first time, the dust (and gas) emission from individual, normal star-forming galaxies at \(z>6\)  (see [8]} for a recent review). In this paper, I briefly review what recent ALMA observations are revealing about the interstellar dust properties of star-forming galaxies in the first billion years.
